Please Help! I swear, I will give you a if you show all ur work! I need help on all these problems, especially the last one!

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36

Asquare picture with sides of 32 inches is to be mounted on a square mat with sides of 52 inches. find the area of the mat that will remain uncovered by the picture.